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3 O F * 




2£ -^ 

22 B '93 


- IN 







Consulting Engineer for Sanitary Works, 

ew York City. 




Copyright by Win. Paul Gerhard, 1886. All rights reserved 

Reprinted from the Ninth Annual Report of the State Board of Health of Indiana 







A serious and all-important problem presents itself to all builders or 
occupiers of suburban and country residences, not located within reach of 
sewers. I refer to the question what method should be adopted by arch- 
itects or householders to get rid of the liquid wastes from the household 
in a manner calculated to avoid at once all nuisance to sight or smell, all 
danger to health arising from the pollution of the soil, the water and the 
air, and all causes of contamination of water courses, whether flowing 
streams, or ponds, lakes, estuaries and harbors. The problem is not at 
all a novel one, for nearly two thousand years ago Hippocrates discussed 
the same subject of the relation existing between health and soil, air and 
water, yet, if we contemplate, for a moment, the numberless filth-reeking 
and disease- breeding privies and barbarous leaching cesspools which we 
still encounter everywhere, and which apparently are accepted as neces- 
sary adjuncts to farm houses, summer residences, mechanics' dwellings, 
etc, we hope to be considered justified in again calling attention to the 
evil results of improper methods of sewage disposal, and in discussing 
briefly the proper remedies. 

Let us begin with a consideration of the smaller farm houses, mechan- 
cottages and laborers' dwellings. The crude methods usually adopted 

}- to get rid of all filth from these are the discharge of the liquids into some 

open ditch, or into some neighboring water-course, brook or pond, and the 
accumulation of the excreta in privy vaults. In other cases, slops are re- 
tained on the premises by pouring them directly in front of the kitchen 
window on to the surface of the ground, which is thus kept continuously 
wet, and quickly becomes saturated with filth, or else the liquid sewage is 

* Copyright by Wm. Paul Gerhard, 1886. All rights reserved. 


stored in leaching cesspools or poured into disused wells. It seems un- 
necessary to explaiu at length the disadvantages and dangers of privies, 
vaults and stagnant pools of slops, from a health point of view. The ob- 
jections against them are well recognized, and hence such devices are now 
utterly condemned by all sanitarians as relics of primitive stages of civil- 

The proper disposal of the slop-water of such small houses is so easily 
accomplished wherever, as is almost always the case, a small vegeta- 
ble garden, or lawn, or grapevine trellis, or an apple orchard adjoin the 
house, as to make us wonder why better methods than those indicated 
above are adopted as yet in comparatively rare instances. In all such 
cases the sewage may, with advantage, be used to feed plants and fruit 
trees, or to irrigate the soil. The ruling principle should be to keep solid 
and liquid waste matters, as much as possible, apart, for this will facili- 
tate the disposal of both. The kitchen water, soap-suds from washing, 
chamber slops, urine, and other fouled water, are easily disposed of by 
a daily distribution in the garden, either by irrigation, or by subsurface 
irrigation. The slop-water should be collected every day in a tight tank 
and carried by hand, or carted in a wheelbarrow, to the garden, and there 
it should be used for watering plants, shrubbery and fruit trees, or for the 
cultivation of garden vegetables. Instead of by irrigation on the surface, 
the slop- water may be discharged into one or more lines of absorption drains, 
laid with open joints under the surface. For the smallest cottage fifty feet 
of absorption tiles are sufficient, and in proportion as the quantity of house- 
hold sewage increases the amount of tiles should be increased. The prin- 
cipal points of importance are that the sewage be applied to the soil while 
fresh and before decomposition sets in ; that it should be applied in moder- 
ate quantities only, to prevent oversaturation of the soil; that the sewage 
Ije applied on or near the surface of the soil, within reach of the oxidizing 
influence of the air and of the bacteria in the soil, and, finally, that the 
application be made intermittent, so as to give the soil, after each dis- 
charge, a chance to breathe, as it were, and to allow the finer solid parti- 
les to be oxidized and destroyed. An easy method of accomplishing the 
disposal of slop-water, where the house contains no plumbing fixtures, is 
to have near the house a hopper or receiver of wood or rustless iron, or, 
better, of earthenware, and provided with a strainer and a proper cover. 
From this a pipe may be carried underground to the absorption tiles, 
while the house sewage may be carried to and di rged into the bopper 
by means of a pail, thus sending rapidly a full volume of slope at proper 
intervals into the absorption tiles. 

The solid excrements are taken care of in the case of'small cottages 
quite as readily and inoffensively by adopting either an earth or an ash 
closet, in place of the usual privy, still so much en vogue, although loug ago 
unanimously mlemned by practical sanitarians. In the application of the 


dry earth system, sufficient dried earth, garden loam, or sometimes coal 
ashes are mixed with the excreta to absorb all foulness, to keep down all 
odor, and to prevent putrefaction. Such earth closets work quite satisfac- 
torily with very little attention, and form a simple and cleanly substitute for 
the privy nuisance. They are manufactured in various grades, and with 
more or less complicated mechanism. As a rule, the simpler the arrange- 
ment, the better. If placed out of doors, the earth closet should not be 
located too far away from the house. The outer structure should be 
strong and substantial, with a good roof to protect it against rain or damp- 
ness. It should be well lighted, well ventilated, not too much exposed to 
the rays of the sun, and preferably plastered on the inside as a protection in 
old weather. A carefully kept dry walk should lead to it from the house, 
and it better to have the walk and the closet shed screened from view and 
from the prevailing winds. The excreta should be received in a movable, 
well tarred v I en box, or else in a galvanized iron pail, not too large, and 
f" sudi shape and construction that it can easily be handled. The box or 
ml should lit close up under the seat, and each time the closet is used, 
ashes or >\vy earth should be used as deodorizers, being thrown down 
either by a bandscooj - or by a mechanical apparatus. There can be scarcely 
any doubt about the economy, efficiency, and convenience of .such appara- 
tus in the case of small houses. The property of dry earth, of not only 
deodorizing, but also absorbing, and rendering harmless excreta of animals 
has long beeu well known. Some difficulty has been experienced in cas< 
where the earth was kept too damp. According to recent observations a 
much smaller quantity of earth is required for earth closets, if the separa- 
tion of the liquids and solids is at once effected. This may be accomplished 
by intercepting the urine under the seat, and removing it by a waste pipe. 
The closet is thereby more easily kept tree from smell, and if properly 
used and well taken care of, it can be located in an extension of a dwelling 
without becoming a nuisance. The dry earth manure ought to be re- 
moved at frequent, intervals, and in summer time it can be used and dug 
under the soil in the garden attached to the cottage. In winter time it may 
be dried in an out-house and can then be applied over and over again. 
Ashes are sometimes used in place of earth, or else finely powdered char- 
coal, which latter is a well known deodorizer. The latter can be applied 
with a mechanism similar to the one used in earth closets and it is claimed 
that only about one-fourth the quantity will be needed. As charcoal is 
rather expensive this is an important consideration. Some also claim that 
removal need not be so frequent in the case of charcoal closets, but this is, 
at best, a doubtful advantage. 

In cottages, or suburban residences of somewhat more pretension the 
earth closet is sometimes located, for convenience's sake, in an extension 
of the cottage, and it then usually becomes desirable to have also a some- 
what more convenient method of disposal of the slop-water, which would 


avoid exposure of the housewife or servant to the inclemencies of the 
weather. This may be secured by arranging a properly ventilated and 
trapped waste-pipe— a pipe two iuches in diameter is plenty large enough— 
to carry the waste from the kitchen sink, the laundry tub, and— wherever 
this is provided for-from the bathtub, into a small receiving tank, located 
outside of the house, and placed below the depth to which frost usually 
penetrates. This tank may be a plain wooden box, or an earthen or iron 
tank, or finally a tank built of brickwork. It may be emptied in the 
plainest kind of an arrangement by hand, or else it may be discharged by 
an automatic device, such as a siphon, a tumbler tank, or other mechan- 
ical appliance. It may become useful, even in the case of small houses, 
to build some sort of a grease trap to prevent the grease from being dis- 
charged and finally clogging the small absorpt n pipes. It , of course, 
assumed that the general topography of the lot is favorable t h an ar- 

rangement, in other words, that there is not a slope from the garden, or 
absorption field, toward the house, in which case disposal by gravity would 
become impossible. If the earth closet is placed inside of a dwelling the 

ime precautions should be observed which are taken in the ca of water- 
closets. The ventilation of the apartment is an important matter, and 
should receive careful attention. As a rule, it is better to locate an earth 

loset in an i iated or detacht part of the ge. While an earth 

closet is inferior to the best water-closet, I have no hesit. m in pronounc- 
ing it, if well taken care of, superior to many water-closets as tmwUy 

aged and kept. 

The <|uestion whether a farm house or laborer's small cottage si 'Id be 
pr ided at il with plumbing work, and above all, whether it is wise I 
have a water-closet indoors, which in turn requir .- a mm pli- 

cated s m of service pipes and a service cistern, i-. re thai n\ thing 
else, one of convenience and i ufort. The annoyance and - >t' frequent 
repairs, and the difficulty in country districts oi etting a n 
such apparatus when out of order, the danger of exposed pip and tra) 
freezing in mid-winter, or sometimes the lack of an abundance of \\ 

lushing, or the nee< ty raising it by hand-pumping— all these re 

con ierati")i- which may ber many from putting an plumbing \ k 

nto their homes. It is undoul Uy much easier ; 1 Less ' les' 

leal with the sewage »lern oi ttaj the strict - parat >1- 

ids ami liquids is adhered t<>. A war i in a house n< I ly n .mres 

i larger discharge pipe than the two-inch waste -«• 1 Ao\> water, but it 

complicates at on i whole arrai That it can de quite 

sa perfectly inodorous and inoffensive it i- not n. ssai ■ I h> 

assert. Those who have Llowed the receni improvements in Iiohm- 

drainage and plumbing rk will kn<>w that it is possible bo sei t a g id 

water-closet and fit it up in such a way as to b< in all n-.-pac sal actory.* 

- • ie auth n PIuij ng . II t \> riage. 


In points of cleanliness I think it certainly stands ahead of any other 
device. Its advantages are many, but its disadvantages under certain 
conditions ought not to be overlooked. If a water-closet is used in a 
cottage, the solids should not enter the outside tank for slop-water, for 
they would soon clog the siphon or the absorption tiles, but they should 
be intercepted in a settling chamber and frequently removed. How this 
may be done will be explained later on when detailed refereuce is made 
to larger country houses. 

The proper disposal of the sewage of larger country or suburban resi- 
dences, fitted up with all the usual plumbing appliances, is often, indeed 
in most cases, a much more puzzling problem. What shall be done with 
the more or less large daily volume of sewage of detached and isolated 
country houses, without creating a nuisance either on one's own premises 
or on those of the neighbors? This is a question of much interest to 
thousands of householders who live in the better class of country or 
suburban houses, and who are often compelled to meet the difficulties as 
best they can. The problem has long engaged the attention of civil 
engineers, who make a specialty of sanitary drainage, and while it i 
possible that the best solution has not yet been discovered, there are 
several methods which are in more or less successful use. Whatever 
method of disposal of the sewage may be adopted, it is obvious that one 
must decide about it before arranging the house drainage system inside of 
a house, for the best arrangement of the main drain and its branches in 
the cellar or basement of a house will depend upon the direction in which 
the sewage tank will be erected, or upon the location of the final outlet 
Generally speaking, an isolated country house, not in reach of sewers, 
may dispose of its sewage by one or the other of the following methods: 

1. It may discharge its sewage into an open surface ditch or gutter, 
removing everything from the house, and carrying the water into a more 
or less distant sink hole, or to some low spot where the sewage is allowed 
to soak away and to evaporate slowly. This method, based on the prin- 
ciple of "out of sight, out of mind," is a very primitive ne, and one 
that has not a single feature of merit. As a rule, such a system becomes 
highly offensive to the immediate vicinity of the house. 

2. The house drain may empty the sewage into a large open or leach- 
ing cesspool, allowing the liquids to ooze away through underground 
porous strata, or by fissures and cracks in the rock. This, although a 
very common method of disposal, is in reality one very dangerous to 
health, particularly so where the water supply is local, being derived from 
a well, a cistern or a spring on the premises. It is a method utterly to be 
condemned as both unsafe and nasty. 


The most primitive form of cesspool is a hole dug in the ground, into 
which all the sewage is continually poured, the result expected being that 
at least the liquids will soak away through unknown underground recesses, 
and disappear. Occasionally the sides of such a cesspool are lined with 
loose stones, laid dry, the liquid sewage escaping at the numerous open 
joints into the surrounding soil, while more or less of the solid matter and 
grease are retained in the cesspool, undergoing at once a very dangerous 
process of decomposition, in the presence of moisture, heat and darkness- 
all conditions known to be particularly favorable to the growth of danger- 
ous bacteria or germs of disease. In dealing with sewage, a cardinal 
principle, always to be observed, is to avoid all stagnation. In the leach- 
ing cesspool we have the worst possible example of stagnation and of 
accumulation of putrefying filth on our premises. The great objection to 
a leaching cesspool is not only that it constitutes in itself an abominable 
nuisance, comparable to a powder magazine, which merely needs a single 
spark to create destruction, but that it unavoidably and invariably pol- 
lutes the subsoil in the neighborhood of dwellings, contaminates the 
water supply, and renders the air which we breathe obnoxious by its 
exhalations. If we consider for a moment that such isolated country 
dwellings and farm houses, which are not in reach of sewers, also do not 
usually "enjoy the benefit of a public water supply, but must derive 
their potable water from wells, cisterns or springs on the premises, 
the full extent of the evil and the force of our objections become 
more apparent. It is, indeed, of the utmost importance that the local 
water supply of isolated dwellings be kept as clear and free from contam- 
ination as possible; but even supposing that water is introduced from a 
street or public supply, the enormous evils of soil pollution and air con- 
tamination remain. Two thousand years ago an old philosopher, Hippoc- 
rates, preached a sanitary formula, which has not been improved up to 
the present day. Recognizing the dangers to health resulting from neg- 
lect of sanitary precautions, he expressed his advice in the words, " pure 
air, pure water, and a pure soil." What, then shall we say if some of 
our best architects of the present day persist in suggesting as the most 
convenient and ready means of getting rid of the sewage of a country 
house the adoption of a leaching cesspool? 

I admit that in sparsely populated country districts a leaching cesspool, 
located at a great distance from, and at a lower level than the house, may 
sometimes be used without causing any harm to the occupants of the 
house. As a matter of principle, however, sanitary science must con- 
demn such devices in every case. If the principle is true that we should 
speedily return all organic dirt and filth to the earth, it should be car- 
ried out in such a manner that the soil may accomplish the complete de- 
struction of organic filth. We shall see, further on, that this can be done 
only near the surface of the soil, and by application of the sewage before 
it becomes putrid. 


In pouring our sewage into leaching cesspools, on the contrary, we bury 
all matter deep in the ground, remote from the cleansing, oxidizing effects 
of the atmosphere, of the purifying action of plant life, and of the help 
which is rendered by some of the low organisms, or so-called bacteria, in 
the process of nitrification and destruction of organic matter. 

Then, again, another important consideration should not be lost sight 
of, namely, that often where a baching cesspool can not work any danger 
to our own house, our own well or spring, it may pollute shallow or 
deep wells belonging to adjoining estates. It is, therefore, evident that 
as habitations are grouped closely together, leaching cesspools become 
more and more inadmissible. If we are selfish enough to locate such a 
cesspool in the remotest and lowest corner of our own garden, entirely for 
getful of its immediate proximity to our neighbor's drinking-water well, 
it is but perfectly proper that our health authorities should remind us 
that we have some obligations to fulfill towards our neighbors. 

Occasionally such cesspools are built with thesides cemented up, leaving 
only the bottom loose for the escape of sewage, or in cases where they are 
originally open on the &ides, the pores soon clog, and the removal of the 
liquid then takes place in a still more imperfect manner. 

3. The house drain may deliver the sewage into a tightly built cess- 
pool, provided with an overflow pipe carried into some ditch or water- 
course. Such an arrangement may be considered a direct outcome of 
the leaching cesspool. Desiring to avoid the pollution of the soil, the 
architect or owner built the cesspool with tight sides and bottom, but find, 
ing that it would rapidly till up, and that frequent pumping out would be 
expensive, an overflow was taken from the cesspool and the surplus of 
liquid sewage carried away. While such a tight cesspool with erflow 
located far away from the house, and with the overflow carried into some 
large volume of rapidly flowing water, may be unobjectionable where but 
little water is used in a house, the arrangement constitutes in the case of 
larger houses a fearful nuisance', for the sewage is already putrid when re- 

4. The alternative is to empty the sewage into a cesspool built abso- 
lutely tight and without overflow. Such a cesspool avoids the pollution of 
the water supply, and also the contamination of the subsoil. It is, therefore, 
an arrangement much to be preferred to a leaching cesspool, and one which 
is permissible under certain circumstances. Perhaps I should rather call it 
a sometimes necessary evil, for it should be borne in mind that it involves 
a long temporary storage of sewage, and does not effect its immediate or 
nearly immediate disposal. Hence it can not be approved from a sanitary 
point of view, and its objections are many and serious ones. Since it is 
the object of all good drainage to get rid of filth from the premises at ^ 


once, or else to dispose of it on the premises while fresh, so as to be com- 
pletely taken up by vegetation and purified by the soil, it is evident that 
a vast receptacle of accumulated filth can not be considered a sanitary 
device. The stagnated sewage within the walls of the cesspool undergoes 
a process of decomposition, and the gases generated are extremely un- 
wholesome, often causing, by improper escape, or by entrance into houses 
through the sewer pipes, a nuisance. To' ventilate such a cesspool suc- 
cessfully is rather a difficult, and often au impossible matter. 

To overcome some of these objections, it is the habit of some architects 
to use two cesspools for a single house, delivering into the one all water- 
closet wastes, while the other one is intended for the reception of kitchen 
and laundry water. I do not approve of such an arrangement. Prac- 
tically, it is found that after awhile both cesspools do not differ materially 
as regards the degree of putrefaction and offensiveness of their contents; 
nor can I see any sense in dupli tiug or multiplying the dangers which 
adhere to all cesspool arrangements. 

There are, however, some cases where no good feasible way of dealing 
with sewage may be devised other than to run it into a tight cesspool. In 
that case, the following precautions are to be observed: The cesspool 
should be located as far away from the house as possible, and there should 
be proper disconnection between the house and the cesspool. The latter 
should be built in two compartment the first of which constitutes an in- 
tercepting chamber for the solids, while the second and larger chamber will 
receive the liquids. Both chambers should be built thoroughly tight, of 
hard-burned brick, laid in hydraulic cement, preferably of a circular shape, 
and the walls should be well rendered inside and outside with Portland 
cement. Each chamber should be arched over and topped with a manhole, 
covered with a tight iron cover. The cesspool should be as well ventilated 
as it is possible to do, and it should be emptied, cleaned and disinfected at 
frequent intervals. The separation of the liquid from the solid matter facil- 
itates much the disposal of both. The liquids may be bailed, or better, 
pumped out, and usect to sprinkle and irrigate the lawn, or kitchen garden, 
shrubbery, vine trellis or apple orchard. The solids should be removed 
and dug as fertilizers under the soil. The oftener this is done the better, 
and the less offense will be caused by the application of sewage tp land. 

Some objections to a cesspool always remain. If it is built, as it should 
be, absolutely tight, and of moderate size only, to avoid the retention of too 
large a volume of sewage, then the necessity of frequent pumping arises, 
and with it the annoyance of constant attention and of manual labor. It 
we enlarge the dimensions of the cesspool to avoid the frequency <>i pump- 
ing out, we increase the dangers always resulting from stagnant sewu. 
and create, as it were, a large gasometer for noxious gases. 

5. If a stream of running wat<-r, either a brook, river, canal or tidal 
* estuary is available, at not too great a distance, a single house may some- 


times discharge its sewage into it, trusting to the dilution of the sewage 
and to the self-purification of the stream to render the sewage innocuous. 
This method, simple and convenient as it may appear, can not be re- 
garded as permissible in all cases. It is a method which, especially 
if the current is not rapid, and the volume of the water in the stream not 
large, may cause serious annoyance and offense, and hence must be con- 
demned as crude and imperfect ; for, by pouring the filth into the nearest 
water course, we simply remove the evil from one place to another, with- 
out attempting to abate the nuisance. Again, it should be remembered, 
that what may be feasible and unobjectionable for a" single house, is not 
practicable in the case of a number of adjoining isolated country houses. 
The pollution of creeks, rivers and streams must be avoided, especially of 
those water courses serving as a source of supply of potable water for 
villages and t wus located along the banks of these streams, and from 
which canal boats or river craft draw their drinking and cooking water. 
Riparian dwellers always suffer by direct discharge of unpurified sewage 
into water courses. The watering of cattle, and washing and bathing in 
the river are thereby often rendered impossible ; while more or less dam- 
age is done to fish culture, particularly where the sewage discharged in 
a putrid condition. While it is a well-known fact that some kinds of fish 
feed on fresh sewage matter, others, particularly salmon and trout, appear 
to be very delicate, and usually suffer from the pollution of streams. 

Channels with tidal flow, finally, should not receive sewage, for much 
of the solid matter discharged into them will repeatedly float up and down 
with the ebb and flow of the tide, instead of being at ODce aud forever re- 
moved. Offensive odors pervade the air, particularly in the vicinity of 
the sewer outfall, the banks will become defiled, the riverbeds silt up, 
and the channels gradually become obstructed. 

6. Houses located at or near the seashore have, sometimes, no other 
available outlet for the discharge of their sewage than the ocean ; but, 
although at first blush a ready means of getting rid of sewage, such a dis- 
charge is seldom permissible. Experience has demonstrated the unpleas- 
ant fact that floating sewage matter, discharged into the sea, may return 
to the shore with the tide, or through the action of eddies, currents, winds 
and waves. The sandy beaches become polluted, and the damage inflicted 
may seriously interfere with the use of the beach for bathing or recreation 
purposes. The direct discharge into the sea is only practicable where the 
sewage outfall from houses on the cliffs or near the beach is carried far out 
into deep water, and all sewage matter carried away by some strong cur- 
rents setting in at right angles to the sewage outfall, or about parallel to 
the line of the beach. 

7. It is obvious, therefore, that in the majority of instances, house 
ewage cannot be directly admitted into water courses or streams of any 




kind, nor into the sea, without creatiDg a nuisance to sight, smell, or a 
danger to health. As far as practicable it should first be purified by re- 
moving the suspended impurities, and at least a part of the matters in 
solution. The purification may be effected by various methods, such as 
artificial filtration, chemical treatment, or by the application of sewage to 
land. After being purified by mechanical or chemical processes, sewage 
can sometimes be admitted directly into streams, in other cases, however, 
it becomes desirable that it be further purified or utilized on laud. 

I shall not stop to consider the question of artificial filter-beds, for, to 
my knowledge, such a system has never been used in the United States, 
in connection with the sewage from houses. I desire only to refer to a 
very ingenious mechanical filter, invented in England, and recently intro- 
duced into this country. It is known as the Farqu bar-Old ham filter. 
The chief characteristic of this machine is the revolving cutt< ich 

so arranged that whenever the surface of the filtering medium clogs up 
with sewage sludge, it can be removed by said cutu in a few moments 
whereb\ practically a new filter is e> Wished. This i ration may 
repeated a* often as found necessary. While I have- not | ually made 
use of this filter for purifying the sewage from isolated count . I 

underhand that it is, or ha- been, in successful use at a coun us< <t 

ibrigl X J- /, and elsewhere. Wherever no e □ of ge 

purification 1 application to land Is possible, 'I believe this method will 
form a su essful solution of the problem, although many will hesitate t 
adopt it. owing to cost. The best filtering material for such appi aus 
is Bawdust, which, when removed and dried an be readily utilized i" firi 
up the hot! eded for the sew; pum] 

Sewage from is«>la 1 country uses may he puriii on tl,. pren - 

hemi ! ti tment. By this met! I the susj ml a art oi 

te d 1 impurii are pr< ted by means of chen Is. Quite a 

large uuj mica) processes have been in 1, but none of 

the attained any very tei use One of t most i mmon 

j -I-'- oi it addition of milk of linn- to sewa • Mu mon 

< e tha us are - lutions of sulphate of alum ii chloride 

< □ Such chemical pr> pitation, while not tnplishing a \<r\ 
t] . ■ purine removes the impi in 1 1 to such an ei at as to pei 

mit a <li iarjre ink* a tirlal ri er or a laj ream isionallv how 

« , as stat above, the clar I liquid i plied to land fur furthei 

In selecting a precipitant, prefereo - il uld be on. which ac- 

complishes tin- { cess- • Bubeidem with r iditj at the saim- time it 
uld i nember. at the precipitant used e >uld produce a aludiri 

minimum hulk w mail mil m amount ■ - lid impurities. In both 
respect.-, milk of lime is .r t th. i - hemicala d i a 


A difficulty adhering to all chemical precipitation processes is the dis- 
posal of the sewage sludge. It usually contains, after precipitation, from 
hO to 95 per cent, of water, and unless the latter is removed it soon de- 
composes and becomes offensive. It has been suggested to evaporate this 
water by artificial heat, but such a process is expensive. Others have 
proposed the separation of the liquid matter from the solid in centrifugal 
machines. In some instances sludge is pumped directly from the precipi- 
tation tanks to land, where it is left exposed to the air, and when com- «. 
paratively dry is dug into the ground. In some patented processes, such 
chemicals are added as enable the manufacture of brick or of cement 
from the sludge. More recently, powerful filter-presses have been used, 
which offer great advantages. By means of these the sludge is quickly 
pressed into cakes', which may be sold as manure to farmers, and not be- 
ing bulky, enable a better transportation for long distances. 

Chemical treatment must sometimes be adopted where land is not 
available for purification purposes, or where its high price precludes any 
effort to obtain au area sufficiently large for irrigation. It may, at times, 
become necessary to resort to it, where the soil is underlaid with rocks. 
Again, chemical precipitation may be combined with the application of 
sewage to land, in which case a much smaller irrigation or filtration area 
is sufficient. But all this refers more to the sewage from large institutions 
or from villages or towns. 

Chemical treatment is not well adapted to single or isolated dwellings. 
The process implies the construction of tanks, the provision of suitable 
chemicals, the careful and thorough mixing of the sewage with the chem- 
icals, all of which calls for considerable expense. Apart from this con- 
sideration, such a manipulation of sewage is not desirable on the premises, 
or in the vicinity of dwelling houses. 

It may be stated in general, that whatever the chemical treatment may 
be, it will be wise not to have too much faith in the realization of a large 
commercial profit from the sewage treatment. Far better to make the 
ultimate purification of the sewage the chief end in view. It is also well 
to remember that in certain chemical processes the effluent water is of 
such a character that, if discharged ii_to brooks or rivers, it may kill fish 
and cause an injury to fish culture. Chloride of lime is particularly ob- 
jectionable. Sulphurous aud hydro-chloric acids are also said to be very 


9. Wherever a sufficient area of land is available, and where the layout 
of the land and the character of the soil are favorable, sewage may be dis- 
posed of and purified on the premises by applying it to the land. Gen- 
erally speaking, the application of sewage to land forms the best solution 
of the problem of sewage disposal. Not that it enables us to derive much 
profit from its utilization — this should always be a secondary consideration, 
in the case of larger institutions or towns not less than in the case of single 


houses— but by applying sewage to land it is always possible to effect its 
purification to such an extent as to avoid the usual fouling of surface or 
subterranean water courses. While chemical precipitation and mechanical 
filtration may be considered artificial processes, the purification of sewage 
by the soil is a natural process, completing one of the constant rounds or 
circulations going on in Nature. The water on the globe furnishes an 
example of such a circulation going on forever. Arising as a vapor from 
the ocean, and from large exposed surfaces of flowing water, it is carried 
along iu the upper strata of the atmosphere by currents of air, and forms 
clouds, from which it is again precipitated upon the surface <»f the earth 
in the form of rain, snow, hail, or dew. A part of this storm water is 
immediately evaporated and returns to the clouds, another part flows off 
on the surface forming successively springs, brooks, rivers, streams — all 
flowing toward the great ocean, while a third part soaks into the ground, 
and is partially absorbed by vegetation, and partly forms underground 
streams of water with an inclination toward some stream, or else forms 
springs, which finally come out at the surface. 

Another example of a constant round in Nature is afforded by the cir- 
culation going on between animal and vegetable life. Plants are nour- 
ished, and grow upon decomposed animal matter, effecting a change of 
those substances which might become dangerous to animal life, into harm- 
less food substances for the roots of plants. The same plants, perhaps, 
form the nourishment for man and animals, and are again discarded to 
feed vegetation. 

The whole process of water circulation has never been better described 
than in the words of Mr. F. O. Ward, at the General Congress of Hygiene, 
at Brussels, in 1856. These words, quoted by Mr. Edwin Chadwick, the 
Nestor of sanitary science in England, in an address on "Circulation or 
Stagnation/' are as follows: 

"The water which falls on the hills in a state of purity undergoes a 
natural process of filtration through sand, enters the rural collecting pipes, 
and passing through the aqueduct to the metropolitan distribution pipes, 
finds its way to every story of every house in the town ; whence again, 
after having supplied the wants of the inhabitants, it runs off, enriched 
with fertilizing matter, which it carries away before allowing it time to 
ferment. This manure, driven along irrigation pipes, is deposited in the 
soil, leaving the water to pass into drainage pipes, and flow on to the 
rivers. The rivers conduct it to the ocean, where it rises as vapor under 
the heat of the sun. to redescend as rain on the hills, enter again the 
collection pipes, and recommence its vast and useful course of circulation." 

Let us return now to the nsideration oi the application oi sewage from 
isolated country houses to land. The conditions of successful application 
are a sufficiently large area of -uitable, absorbent, well aerated, properly 
prepared and thoroughly under drained soil. I should, perhaps, add t<> 


these a few other conditions, namely, the proper and judicious manage- 
ment, careful and equal distribution, and, before all, the intermittent appli- 
cation of sewage to the soil, which latter is so needed to insure its aeration. 

The land selected for the purification of the sewage should not be lo- 
cated too near a dwelling. In particular, if wells are used, it should be 
kept at a safe distance from them, the exact distance depending not so 
much on the configuration or slope of the surface as upon the inclination 
of the underground geological formation and strata. 

We may distinguish several systems, namely, broad sewage irrigation, 
intermittent downward filtration and sub-surface irrigation. The Report 
of the Royal Commission on Metropolitan Sewage Discharge, published in 
1884, defines broad irrigation as " the distribution of sewage over a large 
surface of ordinary agricultural ground, having in view a maximum 
growth of vegetation, consistent with due purification, for the amount of 
sewage supplied." The same report speaks of intermittent downward fil- 
tration as " the concentration of sewage at short intervals on an area of 
especially chosen porous ground, as small as will absorb and retain it, not 
excluding vegetation, but making the produce of secondary importance." 
In the first system, the sewage flows principally over the land, in the latter 
system it passes through the land. Sub-surface irrigation is a modification 
of the filtration system, in which the sewage is distributed in a network of 
tile pipes, close under the surface of the ground, whereby all offense to 
sight or smell is at once overcome. It is obvious that this is an important 
consideration wherever sewage irrigation is to be practiced close to a 


Broad irrigation requires very large areas as land. The land must not 
be continuously flooded, so that in order to manage an irrigation farm 
successfully it is at least advisable to have pieces of fallow land, and to 
distribute the sewage on different portions on alternating days. By pass- 
ing sewage through a properly prepared filtration area we are enabled to 
effect the purification of a much larger volume, provided we maintain an 
intermittent discharge, so as to secure thorough aeration. 

In all methods of application of sewage of land, it is advisable to inter- 
cept at least the coarser suspended organic matters contained in sewage, 
which should be dealt with separately. The irrigation field must in all 
cases be properly and thoroughly under drained. The preparation of 
the surface of the land should be simple and inexpensive, and must de- 
pend somewhat on the general topography of the field, as well as upon 
the kind of vegetation which it is intended to raise from sewage. It is im- 
portant that the sewage be distributed evenly and in as fresh condition as 
possible. Much the best plan to secure an intermittent discharge and to 
avoid an irregular and trickling flow is to collect the sewage from the 
house in a self-acting flush-tank. Wherever possible the sewage should 


be conveyed to the latter by gravitation, and the location of the irriga- 
tion field should be selected accordingly. Occasionally, however, pump- 
ing becomes a necessity, and this may be accomplished either by some 
form of steam pump, or by a gas or hot air engine, or by a windmill. 

I shall, hereafter, dwell more at length upon the sub-surface irrigation 
system, and shall explain some of its details, because I regard it as the 
best available system for the disposal of liquid and semi-liquid wastes of 
isolated country houses. Before doing so it may be well to sum up what 
I have said about the methods available for disposing of sewage of isolated 

countrv houses. 

Such houses as are not in reach of sewers can dispose of their liquid 
sewage in some cases by direct discharge iuto a stream (taking this word 
in its widest significance) or into the sea. As a rule, however, it is abso- 
lutely necessary, and vastly better, to adopt some system of purification 
on the premises. Of systems of sewage purification, application to the 
soil is preferable to mechanical filtration, or to chemical precipitation. 
The latter methods should only be resorted to where no land suitable for 
disposal is obtainable. Of the methods of applying sewage to land, broad 
irrigation is least favorable, as it requires a large area of land, and in 
oases where the field is located close to the house, it becomes objectiona- 
ble. Intermittent downward filtration, while requiring a much smaller 
surface, is yet open to the second objection made to surface irrigation. 
Far preferable, for single houses and isolated institutions, is the sub-sur- 
face irrigation system. Leaching cesspools are absolutely inadmissible, and 
the same is generally true of tight cesspools with overflow- into a ditch or 
water-course. In a few cases it may be necessary to adopt a perfectly 
tight cesspool without overflow, and to pump the liquid out at frequent 
intervals, distributing it on the land. This alternative should be resorted 
to only where all other methods prove objectionable or impracticable. 

In the following I shall dwell more at length upon the disposal of sewage 
by sub-surface irrigation, for, in my judgment, this is the most available 
system for the disposal of liquid and semi-liquid wastes isolated coun- 
try houses. The system has long ago attracted public attention, and has, 
in recent years, been taken up by the foremost sanitary engineers, for 
more than any other method, it promises the entirely successful solution 
of the problem of sewage disposal for isolated houses. It certainly 
recommends itself, owing to the peculiar facilities for disposing of sewage 
a resting an offense to sight or .meU, for it is only too well known 

that open or surface irrigation becomes, in many cases, exceedingly ob- 
jectiouable in close contiguity to mansions or dwellings. 


The origin of the sub-surface irrigation system is usually attributed to 
the Rev. Henry Moule, Vicar of Fordington, the inventor of the earth- 
closet. He looked upon it as the best solution of the slop- water disposal 
'jiiestion for cottages which adopted the earth-closet system. But accord- 
ing to Mr. Edwin Chadwick, sub-surface irrigation had previously been 
tried, independently and systematically, on a large scale, by M. Char- 
pentier, a French vine-grower, near Bordeaux. Mr. Chadwick states 
that the results which the latter obtained with vines and fruits, as well as 
with market-garden produce, were most satisfactory. The system would 
probably never have grown to its present popularity had it not been for 
Mr. Rogers Field, Mem. Inst. C. E., who, recognizing the desirability of in- 
termittent action, invented his automatic Hush-tank, which' he applied 
successfully to the disposal of liquid household wastes. His first experi- 
ments were made at some laborers' cottages, belonging to his own estate 
at Sheffield, iu Essex. Since then the system has been adapted to all 
possible conditions, and has given such satisfaction that it is now consid- 
ered admirably suited to isolated houses not in reach of a sewer, but 
having sufficient porous or well-drained ground about them, with favora- 
1 ile lay of the land. Col. Geo. E. Waring, Jr., was the first to try the 
system in this country, about fifteen years ago. Finding that it worked 
satisfactory in the case of his own residence in Newport, R. I. , then not 
in reach of a sewer, lie adopted it afterwards with success for the disposal 
of sewage of cottages and suburban residences, and on a larger scale for 
the purification of sewage at the women's reformatory prison at Sher- 
burne, Mass., the Keystone Hotel, at Bryn Mawr, Pa., and at Lenox, 
Mass., for the sewage of the whole village. Since a number of years the 
system has been extensively applied by many sanitary and landscape en- 
gineers, and by a few progressive architects, for the disposal of sewage from 
isolated country houses or institutions not within reach of sewers, but lib- 
erally supplied with water and plumbing appliances. 

The system is based upon the well-known fact that the aerated layers of 
soil next to the surface, the sub-surface as it were, possess in a high degree 
the power of destroying organic substances buried in them, by nitrification 
and oxidation, aided during a part of the year by vegetation, and assisted 
at all times by minute organisms or bacteria The latter play an impor- 
tant part in the round of changes in Nature. " They are," says Tyndall, 
"by no means purely useless or purely mischievous in the economy of 
nature. They are only noxious when out of their proper place. They 
exercise a use/"/ and val>"tble function as the burners and consumers of dead 
matter, animal and vegetable, reducing such matter with a rapidity other- 
wise unattainable to innocent carbonic acid and water. Furthermore, 
they are not all alike, and it is only restricted classes of them that are 
really dangerous to man. One difference in their habits is worthy of 
special reference here. Air, or rather the oxygen of the air, which is 



absolutely necessary to the support of the bacteria of putrefaction, is, ac- 
cording to Pasteur, absolutely deadly to the vibrios which provoke butyric 

acid fermentation." 

I lay particular stress upon the importance of distributing the sewage 
close to the surface of the soil, at a depth not exceeding 10 or 12 inches. 
Aeration is a conditio sine qua rum of the whole system. At greater depths 
oxidation and purification become very much slower, until they finally 
cease altogether. The subsoil is not able to effect a complete purification 
of sewage, as the oxidizing influence of the atmosphere does not so freely 
reach it. It is the layer of earth next to the surface, the svb-surfaee, which 
acts on the sewage. Hence the name of the system is derived, and it is 
au error, committed quite frequently, and to which I have more thau once 
called attention, to call the system "subsoil" irrigation. 

We see, then, that only where sewage is distributed close to the surface, 
where sufficient oxygen attaches to the particles of the soil, are the organic 
matters in it taken up as nourishment by the roots of plants, and reduced 
or destroyed by the bacteria in the soil. The liquid sewage, freed of its 
coarser impurities, soaks away into the porous ground, and thus becomes 
still more clarified by filtration, so that when removed by deep under- 
drains, it is generally found to be quite clear, colorless, free of taste or 
smell. By arranging an intermittent discharge, the upper layers of the 
soil are enabled to take up oxygeu during intervals between discharges, 
and to prepare for the next volume of sewage, while the ground is pre- 
vented from becoming saturated, wet and swampy. 

There is a radical difference between such a system and a loose or leach- 
ing cesspool. With the latter the area of soil used for purification is quite 
small as compared with the former, where the surface can be chosen iu 
proportion to the amount of sewage to be disposed of, which is not a feas- 
ible thing to do with a cesspool. We all know that even in the case of a 
leaching cesspool, newly built aud first put to use, some purification of the 
sewage which oozes out at its pores is accomplished by straining and filtra- 
tion. After some use, however, its pores clog up, aud the soil around the 
cesspool becomes saturated with sewage matter, undergoing, in the absence 
T oxygen, a very slow process of decomposition. The sewage soaks away 
unpurified diluting springs and wells, and the unwholesome gases gen- 
erated taint the ground air, and, being given off at the surface, frequently 
euter our houses. It is for these reasons that all sanitarian- look upon a 
leaching cesspool as a nuisance and a standing danger to health. 

Briefly described, the sub-surface irrigation system consists of two parts: 
First — An absolutely tight. eptacle, or sewage tank for liquid liou lold 
wasfc including the content- of wai closets. Second — A net work of 
common distribution drain tiles, laid a i a In-low the surface of the 

ground with open , its, so as to permit the liquid to ooze oul at oumer- 


ous points. This network of pipes, buried in the ground, constitutes the 
irrigation field. 

As stated heretofore, it is an important condition to insure the success- 
fid working of the system, that the discharge of sewage from the sewage 
tank to the irrigation field be intermittent, and that, instead of a constant, 
dribbling stream from the tank, there be a powerful rush of sewage in a 
large volume, so as to secure an even distribution and the perfect filling 
up of all pipes. It is, to say the least, desirable that the discharge should 
not occur more frequently than once a day, that is, every twenty-four 
hours, and the size of the tank should be governed hereby. 

The soil of the field should, preferably, be gravelly and porous. All 
tight clay soils, and ground liable to dampness, should be properly under- 
drained by deep land drains. The sub-irrigation field should not be 
located too near a house, wherever there is abundance of land favorably 
ocated, permitting the sewage to flow away by gravity. As a matter of 
precaution, it is well that some attention be paid, in locating the irriga- 
tion field, to the direction of the prevailing winds, although as a matter 
of fact, a properly working irrigation field is quite inodorous. So much 
is this the case that the tiles may be, and in practice often are, laid under 
the well kept lawns adjoining summer residences, without ever causing 
an offense. Another precaution to be observed where the water supply 
of a country house is derived from wells or springs, is, that the field 
should not be located near them. 

The preparation of the sub-surface of the field is accomplished in the 
following manner: Common, unglazed agricultural tiles, two inches in- 
side diameter and one foot in length, are laid eight or ten inches below 
the surface on continuous boards, or, better, in gutters of ear theu ware, 
laid accurately in the trenches at the uniform grade required. Should 
the tiles ever clog up, it thus becomes an easy task to take them up, t<> 
clean them and to relay them in the gutters, an operation readily per- 
formed by a common laborer. It is quite important that there should be 
between the tiles at each joint, a space of about one-quarter inch to facil- 
itate the oozing out of the sewage. Small earthen caps about three 
inches long are placed over the ends of tiles at each joint to protect it 
from dirt or earth falling from above. It is not necessary to give the 
absorption tiles a greater fall than about two or three inches per 100 feet, 
for if laid at too steep a grade the sewage would rush to the lowest level. 
and saturate that part of the irrigation field. It should be noted that 
much of the success of the system depends upon the accuracy with which 
the distribution tile* are laid. They should branch out from the bottom 
pf the main carrying conduit, and special T or Y branches are manufact- 
ured for this purpose. The main drain should be laid at least two feet 
deep, and the two-inch branches should be cemented until they strike the 
proper depth of eight or ten inches. The main drain conducting the 


sewage from the flush-tank to the irrigation field should be four inches in 
diameter, except in the case of large institutions, when the size of the 
flush-tank often requires a six-inch main conduit. It can be laid with as 
much fall as the layout of the land will require, but when it approaches 
the absorption field its fall should be limited to four or six inches in 100 
feet, to prevent the sewage from running to the lower part of the field, 
overcharging the lower lines of drains. The distance between the lines 
should average about five feet. The ramification and the general layoi 
of the lines will depend on the contour lines of the land. In the case oi 
level ground the lines may be parallel to each other. 

The number of feet of tiles which it is necessary to lay will depend 
upon the quantity of sewage delivered each day. It will vary, more- 
over, for like quantities of sewage, with the general character and poros- 
ity of the soil of the absorption field. Wherever the soil consists of a 
heavy clay, or is liable to be wet or swampy, it is absolutely necessary to 
thoroughly under-drain the field by a complete system of agricultural 
tiles, laid at a depth of from four to five feet, removing and discharging 
the purified sewage as well as any excess of soil moisture. 

The flush-tank is usually built of hard-burnt brick, laid in hydraulic 
cement mortar, and made perfectly water tight. 

An important and most necessary precaution to prevent the clogging of 
the siphon, which empties the tank, or of the distribution tiles, is to build 
in connection with the flush-tank, and between the house and the latter, 
an intercepting chamber or grease trap, intended to intercept all solids, 
undissolved paper and fatty waste matters from the kitchen. Such a 
chamber is, in a certain sense, a cesspool, although it differs from the 
ordinary objectionable device of this kind in having its liquid contents 
frequently changed, and in being built of small size. Its emptying and 
cleaning must, of course, by no means be neglected. Much of the solid 
matters and papers, etc., is reduced by maceration and decomposition, and 
flows dissolved by water into the liquid sewage chamber. The overflow 
pipe connecting both chambers must dip well below r the surface of the water 
level in the first chamber to prevent scum or grease from over-flowing into 
the flush-tank. The flush-tank proper should, generally, be built circular 
in shape, and of a size to hold one day's volume of sewage. The liquid 
wastes from the household are retained in tlii.~ tank until it i< filled, when 
its whole contents are suddenly delivered into the main drain, and thence 
into the irrigation tiles, whereby all the rows of tiles are uniform! 
charged, and the whole of the absorption field is brought into use each 
time the tank is emptied. If the sewage is discharged suddenly in a large 
volume, it oozes out, not only at the bottom, but also at ihe sides and lop 
1 each joint. The purification begins at once. The clarified liquid 
soaks into the ground, the impurities being retained by the earth, where 


they are quickly destroyed. Air enters the pores of the soil and pre- 
pares it for future use, while the tank is gradually filling for the next 

The interval required between two consecutive discharges, the exact 
proportion between capacity of tank and size of house, between size of tank 
and number of feet of drain tiles, etc., are details requiring judgment, skill 
and experience, which must be left to be determined in each individual 
case separately. 

To discharge the flush-tank, recourse may be had to various mechanical 
appliances. The simplest arrangement, but one that requires daily 
attendance and some manual labor, is to place a gate valve at the outlet 
pipe leading from the bottom of the tank, which valve is opened or closed 
by hand whenever the tank becomes filled. This arrangement may 
answer for smaller country houses, in which the amount of water used is 
limited, being usually pumped into the house tank by hand. An automatic 
device is preferable in many respects. This may be either a tumbler or 
tilting tank, or one of several siphon devices now in the market. I have, 
so far, found none better nor cheaper than the annular siphon, as devised 
by Mr. Rogers Field, C E. If space would permit, I should illustrate 
and describe the manner in which I usually arrange it, but this is not 

possible, and I must refer my readers to my illustrated book, "The Dis- 
posal of Household Wastes." 

My description of the system of sewage disposal by sub-surface irriga- 
tion is, 1 trust, sufficiently definite to give a correct general idea of it. 
Having spoken so much in its favor, it is but proper that I should notice 
and mention the objections, which are, at times, brought forward both by 
professional and by laymen against the system. 

1. It is sometimes feared that the land into which sewage is contin- 
ually poured, will, after some years, become saturated with sewage, its 
surface wet or swampy, and the whole of the irrigation field a large ees 
pool, spread out laterally instead of downward. There is, however, abso- 
lutely no reason for apprehending such trouble. Wherever the soil is not 
naturally loose and porous, under drainage is essential and must he pro- 
vided tor. If properly carried out. all superfluous moisture in the ground 
will he removed. Aeration is another essential condition, and wherever 
it is neglected the soil may become saturated with sewage matters. 
Finally, mterm y of discharge is required, with intervals of at le. 
twenty-tour hours between consecutive emptyings of the flush-tank. 
Under drainage of the soil and intermittent action of the flush-tank secur 
the much desired a ration of the sub-surface. This secured, idation 

and nitrification, and the destruction of the organic particles attaching to 
the earth will follow with regularity. 


2. Much apprehension is often felt lest such a m will qoI work 
prop* ■. iu winter tin., and fear is ex pn I about the freezii upoftl 

iiindafa *it the sorption til. Experience with th< %yt m in the 
tides! pai tl n England J- • has fully pen nj doubtson 

i, lL w iju in baa Ihui in continuous m eunimcr ami 

winter, it 03 practical i q* rii a< i the warmth 

i lti nt to I p tin . mnd at the disposal field fi m fi 

3. Ii ie often t( d thai m ■ « »«»t< pti chamfo i foi 
. in i lit v- a spool. Thii is true I Bome extent; rthelea 

I H lw this cham i in connect d wil flu si 

luit I ui pi ■ ition iu it- ( in to i it jm ctl 

tight. Ae i iambi uld b a \» red 

thai : quid a in it is tantlj change d lum 

I I* i' \ III . t imbei 

II) pair. unt i I be com 

w ,,, - f th< lid i r i- urn. ibted r< luced 

l, v | li'jii ami 

II l! :i '•- •• ' d 

B) clean pt ml 

puii inatter n pi : > " ,lli 

mn in \ ill be liit ' l Ml1 ' 

i , nt the nit- p 

I u ' ,\ 1- not 

it at- I i»ropi»i 

I .. Dpi 

il | »t.i 

■ ■ ■ 





! HH J Ml 

tli' i I ' 

.1 . , 

h 1 ;. ; V rlr -l. i I I 

Mi •• >i I I 

& i 





The bottom of the chamber is constructed of concrete, smoothly cemented 
ami rounded, so as to form a sort of channel for the passage of the liquid, 
and to enable the solids to be more readily cleaned out This bottom also 
hits a rapid fall from the inlet to the outlet, which still further facilitates 

the rapid passage of tl liquid. The sides are usually formed of brick- 
work, and the whole is covered by a light wooden lid, opening on a 
hinge." With such an arrangement a mau can easily remove the solids 
by scraping them up by means of a hoe over the edge and raixiug them 
with dry earth. To prevent such a chamber from becoming offensive, 
the solids should be removed daily. 

A different arrangement from the above, which has also been repeatedly 
suggested, is that of haviug in a straining chamber a perforated pail or 
movable iron basket, which intercepts all the solids and which must be 
emptied and cleaned every day. 

Of the two devices, the plain strainer appears to me to be far preferable. 
Personally, I have not yet tried either of the arrangements described. I 
should be willing to substitute the straining chamber for the intercepting 
chamber if I could rely explicitly upon daily removal. * The trouble in- 
volved is not large, it is true, but servants are proverbially neglectful, ami 
the arrangement suggested certainly robs the system of one of its best 
features, namely, that of being automatic. If daily attendance is required, 
it might be just as well to require the help to empty the sewage tank daily 
by opening a gate-valve, and thus do away with every kiud of automatic 
siphon or other device, while retaining the features of intermittent dis- 
charge, and of a discharge of a large volume suddenly distributed over the 
whole of the irrigation field. 

4. Owners of country residences rind an objection to the system in the 
necessity of requent emptying of the intercepting chamber just referred 
to, which, they claim, causes more or less of a nuisance. As an answer 
to this objection, I would say that of the two evils of cleaning out a large, 
ordinary open cesspool and the comparatively speaking small intercepting 
chamber, the latter is far preferable. But in doing so I probably over- 
look the fact that the same people who raise such an objection would prob- 
ably never see to it that their large cesspool is cleaned, paying no atten- 
tion to it as long as the sewage runs off, no matter where to. 

5. It is sometimes objected that the tiles will choke and must be taken 
up and relaid. I can not deny the possibility of such an occurrence, al 
though this may only become necessary about every three years on the 
average. They will choke sooner if they lack the cleansing effect of a 
Hush delivered at intervals from the sewage tank. Even supposing for a 

*Notb.— .Since writing the above the author has constructed su^h a straining chamber as 
is described in the preceding pages in connection with a 30,000 gallon flush-tank lor sewage 
disposal at the State Huiaeoiiathic Asylum for the Insane, at Middletown, Orange county, 
New York. 


moment that the tiles would have to be cleaned and relaid every year, how 
little amount of labor, trouble and expense is involved in doing so, owing 
to their being laid in permanent gutters and close to the surface. Com- 
pare this with the trouble and annoyance of having to empty and clean a 
disgusting overflowing cesspool ! 

6. The system is objected to because the ground where the tiles are 
buried can not be plowed, nor can heavy wagons drive over it without risk 
of breaking or displacing the pipes. This objection can not be denied, but 

it is a slight one, if one at all. 

7. Many people object to the cost of the automatic siphon. However 
expensive this may be, it can not be considered a valid and sound objec- 
tion against the system. Asa matter of fact, the annular siphon, at least 
in the case of isolated suburban and country houses, does not cost very 
much. But, where this expense is objected to, the mistake should not be 
made of providing only one large overflow pipe from the liquid sewage 
tank, from which a constant small stream dribbles toward the irrigation 
field. This is a very imperfect and faulty arrangement. Only a short 
length of the tiles would receive an almost constant trickling flow of sew- 
age, saturating the ground around it to the surface and keeping it in an 
unwholesome condition. Moreover, the tiles would rapidly choke up with 
such an arrangement. Aeration, intermittent action, oxidation, powerful 
flushing, the uniform and entire filling of the tiles, all these conditions 
essential to the success of the system would be absent. 

As indicated heretofore, a stop- valve in the outlet pipe, worked by 
hand, may take the place of an automatic siphon. The only other ad- 
missible arrangement, and one which I have adopted with perfect success, 
for smaller country houses, whore the owners objected to the cost of an 
automatic flush-tank, is a sewage tank, provided with a large number of 
overflow pipes, all placed exactly at the same level in the tank — not a very 
easy thing to do, by the way — and all discharging simultaneously equal or 
nearly equal portions of the sewage into the various lines of absorption 
drains, thus securing a better distribution of the sewage. In this arrange- 
ment the tiles are likely to choke sooner than in the system with inter- 
mittent flush-tank, since they lack the cleansing effect of a sudden rush of 
water from the tank. 

8. Another objection is the cost of the system. The first expense is, 
of course, more than that for a cesspool of moderate dimensions, but tb 
frequently recurring expense of cleaning and emptying the latter s<»'ii 
mnlers the sub-surface irrigation system cheaper than the ordinary cess- 
pool. I r a small country house its whole expense should not exceed 
$250, and for a large country residence the system ought not to cost more 
than $500, which prices include the rovahy on .some of the better class of 
patented automatic flush-tanks. 


9. It is sometimes stated that the sub-surface irrigation system is 
impracticable in the case of level ground, or where the lawn rises at the 
rear of the house, or where the main soil-pipe leaves the house at a depth 
below the cellar floor. To this I answer that some concessions must, 
under such circumstances, be made. For instance, in places where the 
available fall from the house to the irrigation field is slight, no plumbing 
fixtures should be placed in the basement, and the soil-pipe should leave 
the house as near the surface as practicable. In some cases it may even 
become necessary to build the flush-tank in embankment, hiding it in a 
sort of artificial terrace at the side of the house. By making the tank of 
a shallow depth it is usually possible to effect a suitable arrangement. In 
extreme cases it may become necessary to lift the sewage, after straining, 
and this may be accomplished by a variety of mechanical devices. Where 
a small air compressor may be operated in the cellar of the house, Shone's 
sewage ejector appears to offer a simple solution of the problem. Where 
steam is available, a pulsometer pump could be used for lifting the 
sewage. If gas is laid on to the house, or a gasoline gas machine is in 
operation, a gas engine or hot-air engine may prove economical. Finally, 
the motive force of the wind may be used for such purposes by erecting a 
windmill with suitable pumping apparatus. Whatever the special diffi- 
culties may be in each case, they can usually be overcome at a slight sacri- 
fice. Certainly they should not be considered objections to the system as 


10. The objection that the sub-surface irrigation system poisons wells 

may be removed by simply locating the field away from wells, or where it 
must necessarily be close to a house, by abolishing wells, and depending 
on rainwater collected in tight underground cisterns, as a source of water 


11. Some think that it is impossible to purify sewage by turning it 
into agricultural drains located at a depth below the roots of the plants 
It is hardly worth while to consider this objection, as many years of 
successful working of the system seem to amply contradict it. 

12.- The system has received condemnation because "sub-irrigation is 
a process faulty in principle, as it feeds vegetation by the upward rising 
of moisture, accompanied by evaporation, with all the chilling iDfluences 
which are so injurious to vegetation as well as to human beings." I can 
only answer that, so far as my personal observation goes, practically no 
harm has ever been done to vegetation ; on the contrary it stimulates the 
growth of grass, of shrubbery, and of fruit trees, which statement, I am 
confident, is borne out by the experience of other sanitary engineers. 

18. Where the irrigation field is under-drained it frequently happens 
that at first the sewage leaks away too quickly, and without being puri- 
fied, at the points where the distribution tiles cross the lines of agricultural 
tiles. This can be remedied after a while, when the earth in the deep 
trenches for the land tiles settles down and solidifies. 


This, I believe, comprises all the criticisms raised against the sub- 
surface irrigation system. While I do not wish to he understood as 
claiming this method of sewage disposal as a panacea for all the evils 
incident to country house drainage, I hold that the system is an excellent 
one wherever suitable land, of suitable character and of sufficient area, 
properly located, may be obtained. For a more detailed discussion of the 
whole subject I may be permitted to refer to a small volume, recently 
issued, entitled "The Disposal of Household Wastes."* 

*The Disposal of Household Wastes, by Wm. Paul Gerhard, C. E., New York ; D. Van- 
Nostrand Co., 1890. Price 50 cents. 

Works by the same Author. 

The Prevention Of Fire. Second Edition, Price 60 cents. 

The author's suggestions on fire prevention and fire pro- 
tection, although written chiefly with reference to hospitals 
lunatic asylums and orphans' homes, are equally applicable 
to hotels, warehouses, factories, mills, schools, churches, 
dwelling-houses and public buildings of all kinds. 

House Drainage and Sanitary Plumbing. Third Edition, 

revised and enlarged. With Illustrations. Price 50 cents. 

Recent Practice in the Sanitary Drainage of Buildings, 

With Memoranda on the Cost of Plumbing Work. Second 
Edition, revised and enlarged. Price 50 cents. 

The Disposal of Household Wastes, A Discussion of the best 

Methods of Treatment of the Sewage of Fann-Houses, 
Isolated Country Houses, Suburban Dwellings, Houses in 
Villages and Smaller Towns, and of Larger Institutions, such 
as Hospitals, Asylums, Hotels, Prisons, Colleges, etc , and of 
the Modes of Removal and Disposal of Garbage, Ashes, and 
other Solid House Refuse, Price 50 cents. 

Hints on the Drainage and Sewerage of Dwellings. 

Second Edition, profusely illustrated. Price $1*50. 

A Guide to Sanitary House Inspection ; or, Hints and Helps 

regarding the Choice of a Healthful Home in City or Country. 
Third Edition. Price $1.00 

-The six books together sent, postpaid, to any address for 
S4.2S. Address Wra. Paul Gerhard, C. E-, 36 Union Square 
New York City. 

^. *